In order to obtain the benefits of using well-tuned skis, which generally is important to all skiers, and particularly to proficient downhill skiers, the steel edges of the skis need to be maintained in a smooth, sharp condition to provide consistent edge bite. Moreover, the edge angle desirably should be maintained between 85 degrees and 90 degrees, with the specific angle depending upon the skier's preference and upon snow conditions.
A number of different prior art cutting devices have been proposed for sharpening the metal edges of skis. Some of these devices employ conventional files, while other devices employ special cutters. Moreover, some of the cutting devices are designed to sharpen only the outer edges, whereas other devices are designed to simultaneously smooth the outer metal edges and the bottom surface of the skis. These various prior art devices are believed to be either undesirably complex or undesirably expensive, and most suffer from the deficiency of being limited for use in sharpening the edge only to a 90 degree angle. Moreover, those devices which simultaneously cut the outer edges and the bottom of a ski usually employ cutters which form a corner region or pocket into which metal filings can flow. This reduces the effectiveness of the cutter and also creates a situation wherein the metal filing may become embedded in the base of the ski to thereby adversely effect the gliding properties of the ski.
Typical prior art ski sharpening devices are disclosed in the following patents:
______________________________________ Inventor U.S. Pat. No. ______________________________________ R. Luff 3,391,946 F. G. Weeks 3,670,601 D. R. Falkenberg 3,693,219 B. P. Buttafuoco 3,875,825 E. Hanover 3,991,429 A. I. Levine 4,280,378 D. R. Obland 4,442,636 E. V. Lindgren 4,509,297 ______________________________________
Knife sharpeners employing a file and grooves for receiving filings are disclosed in U.S. Pat. Nos. 559,333, issued to Johnson, and 564,403, issued to Whitney.